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Worms!
This page is just to help you to have some insight of a few different types of worms and the damage they can cause if not treated.
Equine Parasites
Types of
Equine Internal Parasites
There are four main types of internal parasites that pass through the horse's body
during their life cycle. Some may cause extensive damage and in the paragraphs
below, I have listed them, the symptoms that the horse may show, and the
recommended treatment for each.
1. Strongyles
The most harmful of these are the large and small strongyles (Redworms and Bloodworms). They are approximately 1/2 inch long (1cm) and are reddish in colour. The larval forms of these parasites may damage the blood vessels and other organs. Young horses are particularly susceptible to large infestations. Equine worming programs are mostly aimed at the control of large and small strongyles.
Symptoms:
o Loss of condition.
o Anaemia.
o Dry, staring coat
o Diarrhoea
o Worms may be visible in droppings
A sample of faeces may be sent to your veterinarian to perform a faecal egg count on a regular basis to monitor the levels of eggs. An untreated horse will become extremely debilitated.
Treatment:
o Oxibendazole, Dichlorvos, Pyrantel Pamoate and Ivermection are effective against large and small strongyles.
o Phenothiazone and Thiabendazole are not as effective against small strongyles as they were, due to resistance build-up.
o Thebenzimidazole anthelmintics are effective against large strongyles.
2. Roundworms
Ascarids, or Round Worms, are stiff, white and up to a foot long (30 cm) in the adult stage.
Symptoms:
o In large numbers, they may cause a loss of condition, irregularity of the bowels or colic.
o In small numbers, they rarely cause any symptoms.
o Young foals from 12 weeks to one year are most vulnerable.
Treatment:
o Piperazines are effectie against ascarids. These are best administered by a veterinarian by means of a stomach tube (known as "tube worming")
o Foals should be de-wormed at eight weeks. It is not necessary to tube worm foals, Telmin paste works well.
o Ivemectin paste is also effective against ascarids but should not be given to young foals.
o All horses over two months off should be de-wormed every 4 to 8 weeks.
3. Pinworms
Pinworms are about 1 3/4 inches long (4.5 cm) and are long and thin and occur in the rectum.
Symptoms:
o Pinworms cause irritation - the horse will rub his tail.
o A discharge will be present and pinworms may be visible around the anus.
Treatment:
o Piperazine, Fenbendazole, Mebendazole (Telmin) and Ivermectin are all effective against pinworms.
o Use paper towels or disposable "wipes" for cleansing the dock area, rather than sponges, to prevent the spread of eggs and infection.
Bots
What
they are...
During the summer and early autumn months, you may notice the appearance of
small yellow-ish dots (gasterophilus) are the larvae of botflies which the
botfly lays on the hair shafts on the chest and forelegs of the horse's coat. .
The eggs hatch in 10 to 14 days Botflies are particularly annoying to horses,
causing them to stamp and bite at themselves, the horse will lick them off his
coat and transfer them to his mouth, where the larvae burrow into the mucous
membranes of the lips and gums. There they remain for a short growing period
and then they pass on to the intestine where they attach to the stomach wall.
They remain there for almost a year before passing out with the faeces to
pupate in the soil. Adult botflies then emerge from the pupa cases in 3 to 9
weeks, depending on the temperature.
How they infect the horse...
This biting action of the horse stimulates the larvae to hatch from the eggs
and the horse then, in the course of his licking and biting, takes the larvae
into his mouth. Once in the mouth, the larvae burrow into the cheeks and tongue
of the horse, where they remain for about three weeks. While in the mouth they
do not appear to cause any discomfort or worry the horse.
From the mouth, the small larvae migrate to the stomach, where they develop into larger larvae. They attach themselves to the stomach wall by their teeth. They stay in the stomach all winter, and can cause gastritis and even perforation of the stomach. In the spring, they release their hold and pass out in the manure to develop into adult flies and begin the life cycle again.
How to control them...
Horse owners can control the infestation of their horses by use of a bot knife
to remove the bot eggs from the hair on a daily basis during the fly season. In
addition, modern dewormers containing ivermectin are efficient at killing the
larvae that reach the stomach. For this reason, many veterinarians advocate the
rotation of dewormers to include products containing ivermectin, such as
Eqvalan, Zimecterin or Equest (UK), in the fall and again in the spring for
maximum efficiency.
Symptoms:
o Large quantities in the gut will cause a loss of condition along with a dry, staring coat.
o Temperature and pulse rate may rise.
o The horse may shows signs of colic - restlessness and kicking at belly.
o Intermittent diarrhoea or constipation may be apparent.
Prevention:
o Keep horses off pasture when botflies are laying their eggs. Turn horses out after dark and bring in early in the morning.
o Pick or clip the eggs of the coat as soon as they are seen.
o Frequent grooming removes some eggs.
o Provide pasture kept horses with a darkened shelter during the botfly season.
Treatment:
o Dichlorvos, trichlorfon and carbon disulphide, administer by stomach tube, are effective in controlling bots. This should be done in early spring when the larvae are in the stomach and before they pass out of the horse in the faeces.
o Ivermectin paste and mebendazole-trichlorfon (Telmin B) paste are also effective against both the stomach bots and the earlier migrating stages in the mouth tissues.
Rotating
wormers
It is a well known fact that large and small strongyles develop resistance to
wormers and therefore it is generally recommended that wormers be rotated by
chemical class, not just brand name, in an effort to lessen the occurrence of
resistance. With the help of your veterinarian, who will perform a faecal egg
count to determine the numbers and types of parasites you are dealing with, you
can formulate an effective program of parasite control.
Pasture Management
As i live in England one of our regular tasks was to go around the pasture with
a wheelbarrow and remove all the droppings. We do this every other day, as the
climate in England rarely produced the hot, dry weather needed to kill the
eggs, which would stay viable within the moist droppings until the flies were
ready to hatch and start their life cycle again.
o Other pasture management techniques are to graze other animals on the pasture. Only horses are affected by redworms. Other animals, such as cattle, will ingest the eggs and interrupt the life cycle, thereby reducing contamination.
o Ploughing and cropping for a year or two with a straw crop